Informed consent in the candesartan antihypertensive survival evaluation in Japan (CASE-J) trial: A survey of collaborating physicians

An anonymous postal survey was conducted among the physicians collaborating in a randomized conled trial to examine their method of convincing patients, their consent process, the factors related to higher accrual, and the predictors of 100% success in the process of obtaining informed consent (IC). A total of 512 questionnaires were sent out and 448 responses were received, for a response rate of 87.5%. The 448 physicians solicited a total of 5,371 eligible patients (12.0 per physician), among which 3,763 patients (8.4 per physician) agreed to participate. One-fifth (22.3%) of the physicians were able to obtain IC from 100% of the patients they solicited. Physicians who thought that the information on the IC sheet was sufficient to obtain consent (odds ratio [OR]=2.0, 95% confidence interval [Cl]=1.1-3.9; p=0.03) and those who did not consider that the patient's decision was influenced by relatives and friends (OR=0.2, CI=0.1-0.4; p=0.001), were significantly more likely to obtain IC from 100% of the eligible patients. Three-fourths (73.2%) of the physicians targeted only patients who they perceived would easily provide IC, and 81.2% favored some form of incentives for patients. The results of this study should be useful for efficiently implementing randomized controlled trials in Japan.